The present invention relates in general to a communication system that provides an automated and simplified interface between a vehicle and an emergency response center, and more specifically to controlling the message system to place a second call to the response center using only voice contact and bypassing data transmission via modem in the event that a first data call is unsuccessful.
The use of transportation vehicles such as automobiles on roads and highways inevitably involves some number of breakdowns or collisions, or situations involving health difficulties of a driver or a passenger in which roadside vehicle service, such as a tow truck, or emergency assistance, such as police, ambulance, or fire, are needed. A means of summoning help is desirable in such situations and the availability of radio communications has been very beneficial in that regard. Cellular telephones are often installed or carried in vehicles by their owners for this reason.
The response time to a request for help should be minimized to meet any potential need for critical services. Accurate information must be provided to the emergency service provider to permit effective and timely response. However, many cellular phone callers to emergency services are unable to provide their location accurately in a timely manner. In addition to position information, a service provider benefits from having information on vehicle identification, cellular phone number of the telephone in the vehicle, the cellular system identification from which a call originated, and speed and heading of a vehicle.
Automatic position locating systems such as a global positioning system (GPS) receiver have been utilized in conjunction with a cellular telephone unit to provide position information over a cellular link (see U.S. Pat. No. 5,043,736, for example). However, prior systems have failed to adequately automate operation of a communication system to sufficiently reduce the burden on the vehicle operator to follow a rigid operating procedure or provide certain information to the service provider. Such complexity has limited the effectiveness of such systems, especially when the user is in a stressful emergency situation or unable to respond.